Lubricating oils and the like



Patented Nov. 28, 194.4

7 2,363,514 LUBRICATING OILS AND THE LIKE Bruce 'B. Farrlngton and James 0. Clayton,

Berkeley, and Dorr H. Etzler, Albany, CaliL, assignors to Standard Oil Company of California, San Francisco, Calif., a borporation of Delaware No Drawing.

Application December 3, 1942, Serial No. 467,778

19 Claims. (01. 252- 39) This invention relates to new and useful compositions of matterand to methods of preparing the same. In particular, it relates to compositions comprising hydrocarbons of the lubricatin oil class, in major part, in which are dissolved or suspended minor amounts of certain metal salts of organic aliphatic carboxylic acids, either alone or in, admixture with other compounding agents of the same or different type.

This application is a continuation-in-part of our copending application Serial No. 322,946, filed March 8, 1940, now Patent No. 2,349,817.

It has long been the desire of the lubricating oil compounding art to obtain an oil, particularly of petroleum origin, which alone or with the addition of relatively small amounts of compounding agents, would resist deterioration or degradation when subjected for long periods of time to high temperatures and pressures, in the presence of metals, air or oxygen, or hydrocarbon partial combustion products. Deterioration of the character referred to here manifests itself in diverse effects, dependent upon the nature and degree of refinement of the hydrocarbon oil and upon the environment to which it is subjected, but reference may be made to Diesel engine piston ring sticking, in which the exposure of a lubricating oil to such temperatures as 425650 F., in the presence of oxidizing combustion gases at pressures as high as 750-1150 lbs/sq. in., causes the deposition of oil degradation products of such a cementitious character as to effectively take piston rings out of service; to the deposition of sludge from automobile crankcase oils, apparently as the result of oxidation and/or polymerization phenomena; and to the corrosion of metal bearing surfaces, apparently as a result of phenomena which cause the formation of organic acidic products. This situation is aggravated by the fact that improvements in the mechanical arts have brought about increasing severity in the conditions to which hydrocarbon oils are subjected, and by the fact that oil compounding designed to eflect a stability in one direction often brings about a marked instability in another.

It has been found that the addition to a lubrieating oil of small amounts of a metal salt of an aliphatic carboxylic acid, carrying in addition to the salt-forming carboxylic acid group a carboxylic or dithiocarboxyiic group, which is free or is neutralized by a basic atom or group of atoms, brings about an improved stability in bydrocarbon oils when the same are subjected to high temperatures and/or pressures in the presence of oxygen and metals. Such salts may be viewed as salts of acids of the type or HSSC-(CH2)n-COOH, in which 12 may be zero or a whole number, preferably not greater than three; in which there may or may not be alkyl, aryl, aralkyl or aliphatic carbocyclic substitution to increase 011 solubility; in which the right-hand COOH group is converted into a metal carboxylate group and the left-hand COOH or CSSH group is a free or neutralized carboxylic or dithiocarboxyllc group. It has been further found that still greater improvement of the desired sort is brought about when in such metal salts certain polar substitution is efiected in a position alpha, beta, gamma, delta or even epsilon to the carbon atoms of a salt-forming carboxylic acid group, the effectiveness for the desired purpose decreasing in the orderoi' positions as recited.

' Viewed from another standpoint, the salts of this invention are metal salts of substituted aliphatic carboxylic acids capable of representation by the partial formulain which M is a metal, including the. hydrogen equivalent of a polyvalent metal, the group COOM is attached to ,an aliphatic carbon atom, the carbon atom to which the group cm is attached is an aliphatic carbon atom (preferably alpha, beta or gamma in respect to the COOM group), X is oxygen or its analogue sulfur and Y is hydrogen or a basic atom or radical. The salts of the invention are, therefore, metal aliphatic carboxylates substituted, preferably in the alpha, beta or gamma position, by a free or neutralized carboxyl or dithiocarboxyl group.

Referring to additional polar substitution of the salts of the invention, the following polar radiin thesalts of the invention as indicated:

Formula Name alio x0 or keto..- =0 Carbamyl -CO(NH;) Alkyl or aryl thiolcarboxyl. COSR 1 Aikyi or. aryl thionocarboxyl. --CSOR ercapto -SH Aikyl or arylthio BR Dithio SS- Suliinyl =SO Sulfonyl. =S0r Iminom' =NH Alkamino or arylamino. NHR Diaikamino or dierylemlno. -NR; Azo -N=N- -.-NHNH- =N- H! -NN H, -NNN ON -NC -0ON NCO -SCN -BNC NO NO: =NOH -=NHOH NON -NO 0H Phosp PH1 or =PH 'Phosphoroso 0 Phos ho P 0, Alky or aryl phosphate OP0(0R); Alkyi or aryl phosphite. 0P(0R icyl 1H: Siiicylene =SiH, Aikyl or aryl silicone Si0OR Alkyl or aryl sulflno. B0|R Alkyi or sryi sulio SO|R Alkyl or aryl suliamino. NHSO|R famyl... -B0,NH, Suifonamido SO|NH- S enyl Y --SeH Alkyi or aryi selenyl SeR Beleno =Se Seleninyl. Se0 Belenonyl... =B60| Alkyi or aryl Alanine -Be0( Alkyl or aryl Se0| OR) Science and e0 Tellury -TeH Alkyl or aryl telluryl. 'leR. fl i z i ""'i"li""b"fiitt P on or cry p cap 0 s Alkyi or sryl phospnonate P )1 Alkyl or aryl phosphinite =PO Alkyl or aryl phosp hlnat =POOR Phospham -PN Phosphoro.- -PP Phosphoarseno -PA Arsinn' Alg: or =AsH Alkyl or aryl antimonate. -0SbO(OR);

lor aryl stibono..- -8b0 OR):

Alk l or aryl stibinico. b0 Ant mono bS Stibarseno --SbAa Bismuthino -BIH, or =3!!! Boryl.. Alkyl or aryl borate 0B(0R)1 Alkyl or sryl icste OSi(OR)'1 Iodoso I0 Stannyl SnH Iodoxy I 0:

aseaua whole number, and the methylene groups being I in some cases substituted by oil-soiubilizing groups and/or polar groups as hereinabove indicated) there may be mentioned: the oxalic series methyltricarballylic or camphoronic acid, and the alkylic homologues thereof, and the olefin tricarboxyiic acids such as aconitic acid and its isomers aceconitic and citracetic acids; also the sulfur analogues ofthese acids in which one or two of the COOH groups is replaced by a CSSH group. Representative of hydroxy substituted polycarboxylic acids (acids in which one or more hydroxy groups are the polar groups referred to as especially beneficial) are tartronic or oxymaionic acid and the several alkylic tartronic acids such as methyl, ethyl, propyl and isopropyl tartronic acids, malic acid and its homologues, such.

as isopropylmalic acid and the paraconic acids, the aand ,e-oxyglutaric acids, the a-hydroxy adipic and sebacic acids, the tartaric acids; citric acid. and dioxytartaric acid; also the sulfur ana-. logues of these acids in which one or more (but not all) of the COOH groups are replaced by a CSBH group. Representative of unsaturated polycarboxylic acids (acids in which one or more vinylene or ethynylene groups are the polar group referred to) are the alkylene-malonic acids such as methylene malonic acid, CHa:C(COOH)2, isopropylene maionic acid and allylmalonic acid, CHz:CH.CH:.CH(COOH)2, fumaric and maleic acids, mesaconic, citraconic, itaconic and glutaconic acids and their alkylic and dialkylic homologues, diallylmalonic acid, muconic acid, glutinic acid anddiacetylenedicarboxylic acid; also the 7 EXAIWPLES; SET I v Among the beneficial efl'ects which flow from Q the incorporation of a metal salt or a mixture The metals whosesubstituted carboicyiic acid tin and zinc'have been found of particular utility. Among the aliphatic carboxyllc acids whose aluminum, chromium, cobalt, lead, manganese,

of metal salts of the above described aliphatic acids in a hydrocarbon oil of the lubricating oil class is the prevention of piston ring sticking,

or its marked postponement, under very severe under extremely severe conditions, designed to develop fully the tendency of the crankcase lubricant to deteriorate with gum formation and piston ring sticking: operation was at 1600 revolutions per minute; engine jacket temperature was maintained at 375 F.; crankcase oil temperature was maintained at 220 F.; at periods of 15 hours the operations were interrupted and the condition of the piston rings determined. In Table I, the base oil referred to as "Western 30 was an acid-refined lube stock of California origin; A. P. I. gravity 21.4"; viscosities at 100 and 210, 622 seconds and 56.6 seconds, respectively, Saybolt Universal. To this tion of agents other than those of the invention (oils A, B, C, etc.), in which the compounding, while perhaps of benefit in respect to some property of the oil, is of definitely deleterious base oil were added the various salts in the efiect in respect to the corrosivity of the oil toamountsindicated, by weight. ward bearing metals.

TABLE I Prevention or postponement of piston ring sticking Hours to Relative ring Relative Example Oil cause ring slot cleanlipiston clean sticking ness liness Western 30 +0.63% Ca a-eicosyltartrate 60+ +0.50% Ca a-cetylmalonate 75 +0.50% Ca a-cetenylsuccinate 90 +0.34% Ca a-eicosenylsuccinate 120+ +0.50% Ca eetylphenate+0.50% Ca a-eicosyltartrate. 120+ +0.50% Ca cetylphenate+0.50% Ca a-eicosenylsuccinate 60 Note: A plus sign the stated hours duration.

EXAMPLES,'SET II Among the further benefits to be derived from the addition of the metal salts of the invention to hydrocarbon lubricating oils is a decreased corrosivity toward bearing metals, particularly nooc-wnm-coon HSSC-(CHa) n-COOH (n-=0-8 or a higher whole number) in which a polar group or radical as above exemplified is substituted for a hydrogen atom attached to a carbon atom in close proximity to the carbon atom of the salt-forming carboxylic acid radical, preferably in the alpha position, less preferably inthe beta position and of decreasing desirability and effectiveness in the gamma, delta, epsilon, etc., positions, in the order named.

In the tests whose results are summarized in Table II, thin sheets of the indicated bearing metals were cut into strips (copper-lead, 4 x1 34," x 3& cadmium-silver, x 1%" x .41:"), and these strips were immersed in the exemplified oils'carried in 2" x 20" glass test tubes; these test tubes were carried in an oil bath maintained at 300 F. i-l F. Each test tube contained approximately 300 cc. of oil, and

' air was bubbled through each tube at the rate of 10 liters per hour. At the end of each of three 24-hour periods, the strips were removed from the oils, washed with petroleum ether and carefully wiped with a soft cotton clothj weight following a stated number oi hours in the antepenultimete column indicates free rings at the conclusion of a test of TABLE II Reduction of corrosivity to bearing metals ViVneight loss mgma, Exon 72 hrs. ample Cu-Pb Cd-Ag Q Western 30 13.0 0. 4 l0 +0.03% Ce a-eicosyltartrate. 5. 0 0. 9 l5. +0.50% Ca a-cetylmalonate. 9.8 0. 3 l6 +0.50% Ga a-cetenylsuccinate 1. l 0.3 17 0.34% Ga aeicosenylsuccinate l. 6 0. l 42"... +0.50% Ca cetylphenate 0 50% Ca a-eicosenylsuccinate. 40. 7 6. 0 A +0.50% Ca stearate 131. 9 180. 5 B +1.0% A] dinaphthenate. 67 113 O +l.0% Mg naphthenate 139 119 D.. +10% Ca cetylphenata. 126 12.1

EXAMPLES, SET III A still further benefit to be derived from the addition of the metal salts of the invention to hydrocarbon oils, particularly noticeable in the case of salts of those acidsflcarrying polar sub-- stituents as described, is a marked lessening of color instability upon exposure of the oils of the invention to heat, in the absence of air or metals.

In the tests whose results are summarized in Table III, samples of the exemplified oils were held, in glass, at 300 F. for 6 hours. The oils were cooled at the end of this period of time and their colors measured. for comparison with the uncompounded base oil stocks; A. S. T. M. colors, MethodD-34T, were recorded in all cases.

Tun: In

Color stability Examp19 Oil Western30.-. 10 +0.63 Ca a-eicosyltartrate +0.34 Ca u-eicosenylsuccinate" 24 +0.13 q Ca -cetenylsucclnate.... 29 +0.50 K a-cctylmalonate 41 +0.50 0 Ca cetylphenate+0.l0%

Ca a-cetenylsuccinate 42 +0.50% Ca cetylphenate+0.50%

Ca a-elcosenylsuccinate 7 53 +0.25 Ca cetyl hos hate+ 0.10 Ga a-ceteny succ ate 4 14 54 +0.25 Ca cotylphosphate+ 0.50 a Ca a-eicoseny1succinato. 4- l- 63 +0.50% Ca cetylphenate+025 o Ca cctylphosPhate+0.20% a woman lsucc 64 +0.50% :1 cetylphenate+0.25% Ca cetylphosphate+0.50% Ca a-eicosenylsuccinate, 7 2% 71 +10% diisoamyl tsrtrato+0.l0

Ca a-cetenylsuccinete 4% 1 72 +10% dliscamyl tartrate+0.50%

Cs a-eicosenylsuccinate 3% M,

EXAMPLES. 'SE'I IV In many cases still further benefits may be derived from the incorporation of the metal salts of the invention to hydrocarbon oils, by reason of an enhanced oiliness and/or an increased load carrying capacity of the oils so compounded.

In the tests whose resultsare summarized in Table IV, the figures reported under Weeks wear are those obtained in the operation of a Weeks wear testing machine, in which a /2 inch steel ball is pressed against a 1% inch steel cylinder which is rotated at 600 revolutions per minute and which dips into the oil being tested; the dura tion of the test is 16' hours and the body of oil is held at300 F.; the results are reported in inches oi wear X 10 as measured on the cylinder. The figures reported under Film strength are those obtained in the operation of a Timken machine asdescribed in the S. A. E Journal, volume 28,

EXAMPLES, SET v In the tests whose results are reported in Table- V,the oils referred to were subjected to the "oxidator test" particularly described in the Journal of Industrial and Engineering Chemistry, volume 28, page 26, 1936, at.34;0 F.'. which conditime may be noted as extremely severe. The results of the, tests are reported in cubic. cent meters of oxygen absorbed per 100 grams or therespecti e one. at the periodsot time indicated,

TAIL! V Reduction of orwen. cbsomflon V Oxyg'enubtorption on 1 is. 22m. 30 200 300 Cs e-elcosyltartrate 65 122 Cs a-cetylmalonate 40 150 17 %Ca a-eicosenylsuccinaten- 23 65 26 +0.25 Ca -cetenylsucciuate.. 8 47 31 +0.? 0 Ca a-eicosylamlnosuccin- 100 290 8 I Thereare given below the structural formulae of a few typical salts of this invention, from which the relationship of structure (illustrated by the formulae) to performance (illustrated by the spe ciflc examples) will be made more clear:

Calcium aipha-eicosyl-tartrate c o o 4 Hi l 0H CnHn-(J OH/C5 t 0 0 7 Calcium alpharcetyl-malonate e00 CuHa-C Ca 35 Calcium aJpha-cetenyl-succinate v ;in\ 4 EF/ Calcium alpha-eicosenyl-succinate 000 page 53, 1928; the results are reported in pounds at failure. H ca TABLE IV 1!: CH: Wear resistance and film st ength (:00

Calcium a1 ha-eicos l-aminosuccinate Exon Weeks Film p y ample wear strength Q00 WesternSO 288 I 120 J l5 +0.50" Ca a-cetylmalonate 143 160 4 H Ca 17... +0.34 0 Ca c-eicosenylsuccinate 106 220 an-$5 i 25"..- +0.20% Ca amtenolsuccluate 163 120 v B +1.07 Al dinaphthenatm; 639 120 D- +0.50 0 0a cetylphonate 105 12) 00 Calcium alpha-eicosyl acid tartrate .7

50 H on H0 11 cm..- on no C|0Hu OOH noo Calcium alphaycetyl acid malonate '1 1 c'oo-ca-ooo T Clea 8r- H E -CuHu Calcium alpha-elcosenyl acid succinate ooo-cs-ooc 1 cuau cn=caa 1: H5 Hi6 l 70 500i I goo Calcium alpha-eicosyl-amino acid succinate COO-Ca-OOC H NH! HSN H Qn ir- E H CmH41 OCH OCH Calcium alpha-eicosyl dithiotartrate COO som

Calla-i Calcium alpha-cetyl dithiomalonate 000 C1tHaxCH Ca o s s Calcium alpha-eicosenyl dithiosuccinate coo C|sHa1'CH=CH( )H CE: is/

Calcium alpha, beta-dihydroxy-beta-dithiocarboxy 'tricosanoate' c s s H HS s 0 Calcium alpha-dithiocarboxy stearate COO-Ca-00 c CioHsi- H S SE C-CmHa:

HS s c Calcium alpha eicosenyl beta dithiocarboxy propionate- As exemplified by the above structural formulae, the salts of the present invention all contain a. metal carboxylate group COOM attached to an aliphatic carbon atom'; there is also present a free or neutralized carboxyl or dithiocarboxyl group close to the salt-forming COOM group.

(In the salts just exemplified, the metal is calcium and in several of the salts the same calcium atom serves to neutralize two carboxyl groups or a carboxyl group anda dithiocarboxyl group, but other metals than calcium may be used, and in those salts having two metal carboxylate groups or a metal carboxylate group and a metal dithiocarboxylate group, two difierent metals may be present, one in combination with a carboxy group and the other in combination with a sec-- 0nd carboxyl group or with. .a dithiocarboxy group.) molecule an oil solubilizing group, exemplified by the eicosyl, cetyl, cetenyl and eicosenylgroups, and in certain of the salt molecules there is present in addition to the carboxyl and dithiocar- 'boxyl groups one or more polar groups, exemplifled by the hydroxyl, amino and vinylene groups, in close proximity to a metal carboxylate (COOM) group. 011' solubilizing and polar Also, there may be present in the salt groups, such as those exemplified, are not essential to the practice of the invention but their presence is advantageous. Alternative oil-solubilizing and polar groups are indicated herein-,

above.

.A few typical instances of preparation of the salt additives of the invention and of the manner of compounding such salt additives with hydrocarbon oils for the purpose of preparing concen trates or finished oils will serve further to illustrate the practice of the invention.

Calcium alpha-petylmalonata-The malonic ester synthesis is employed (cf. Leibigs Annalen der Chemie, vol.2'04, p. 121), involving forming the sodium derivative of malonic ester, reacting the sodium derivative with cetyl iodide, hydrolyzing' the resulting alpha-cetyl malonic ester with aqueous KOH to produce the potassium salt, and precipitating the calcium salt by adding CaClz solution to a suspension of the potasium salt in a 50-50 alcohol-water mixture.

Calcium alpha-alkenzll succinates.-These alkenyl succinates, exemplified by the cetenyl and eicosenyl members, are prepared by the Diehls and Alder method (cf. Liebigs Annalen, vol. 460, page '68, and vol. 470, page 62; also Berichte der deutschen Chem. Ges.,- vol. 62, page 554), involving condensing an olefin (such as C16 or C20 olefin polymers) with maleic anhydride under' can be prepared by the method given in Gilmans Organic Chemistry," 2nd ed., page 931. See also Bruni and Levi, Atti Acad. Lincei, vol. 32, pt. 1, page'5 (1923) and Bloch, Kuhn and Bugge, J. prakt. Chemie, vol. 82, page 473 (1910) By this 'methodan aldehyde (which, for the purpose of preparing the carboxy compounds of the type referred to above, also contains a carboxyl group) is reacted with ammonium disulflde. An illustrative preparation is as follows: To an aqueous solution of ammonium Iormylacetate add an excess of ammonium disulfide, allow to stand several days and then heat to remove water, am-

monia and ammonium sulfide, and crystallize out the ammonium salt of dithiocarboxy acetic acid or add to the aqueous solution of ammonium salt an aqueous solution of a polyvalent metal salt to precipitate. a polyvalent metal dithiocarboxy acetic acid. The equation for the reaction is as follows:

c t s n +(Nn.), s, yJ-S-NH. -i- NHiOH 00NH4 H,

' COONHi Ammonium iormyl I Ammonium dithiocarboxy acetate I acetic acid Examples Jot useful hydrocarbon oil compositions containing the above salts, with and without other compounding agents, are as follows:

' 1. om ss n a Parafflnio oil +1% Ca e-cetyimalonate 2 it +1% Ba a-octedecyisuccinate 3. Ditto... +1 Zn a-dodecylglutarats 4. Ditto +1 Cr B-ootyladipete 5. 99% SAE 30 naphthenic oil +1, Ca c-cetcnylsucoinote 6. Ditto +1 Ca wcetyimaiate' 7. Ditto... +1 0 Zn c-octadecyltartrate 8. Ditto.-. +1 Ca a-cet laminosucclnatc 9. Ditto..- +1 0a a-d ecyltricarballylate 10. 99% BAE m mixed base oil +1z, Ba s-dodecylcltrete 11. Ditto +1 0 Ca agarate 12. +1 0 Zn n,-cetylaconitate 13. 1 Ca s-cetylmercaptosuccinate 14. Ditto +1 Ca -cetyldithiomalonate 1 Co u-cetylmaionete 98% SAE napbthenic oil +1 0 Ca cetylphenam D l; +1 0 Ca wcetylmelonate +1 Ca cetylphos hare 17. 98% BAE 30 naphthenic oil +1 08 mate +1 Co cetylphenol sulionate +1 0a c-cctylmalonate l8. Ditto--. g g i fi r. 8 '06 y to (18$ mm +1,,, dihy droxy diplienylsulfide Generally, measurable improvements in the properties of hydrocarbon oils are obtained by the incorporation ofas little as 0.1% 01 the agents of the invention, but amounts between about 0.2% and 2.0% oi the agents, by weight based on the oil, are preferable, dependent upon the degree of inherent tendency toward degradation of the oil itself or as otherwise compounded; amounts higher than about 5.0% are regarded as unnecessary in the best practice orthe invention. v

A feature of the invention is in the preparation and distribution of bases or concentrates containing relatively large proportions of the additive agents in admixture with hydrocarbon oils or the lubricating or less viscous types or, ii'more -mands. In the preparation of either the finished oils of the invention or the bases or concentrates referred to, complete or clear and homogeneous solution is not always necessary: blending agents ing temperatures encountered in the operation of internal combustion engines, containing dissolved in the oil a small amount, sumcient to retard said deterioration, of a metal salt of an allphatic carboxylic acid, said metal salt carrying,

on an aliphatic carbon atom not more than about two carbon atoms removed from a metal carboxylate group, a substituent selected from the class consisting of the tree carboxyl group, the

9 free dithiocarboxyl group, and neutralized carboxyl and dithiocarboxyl groups.

2. The oil of claim 1, wherein said substituent is a free carboxyl group.

a. The 011m claim 1, wherein said substitu- 1 tdon of internal combustion engines containing a or homogenizers may be employed if desirable, to

prevent sedimentation oi the more oil-insoluble of the agents, but it has been found the possible detrimental eflect of the presence of filter-able insoluble materials 01 this character, if indeed present, is determined largely by the particular conditions attending the contemplated use, and that their presence is not in all cases deleterious to the functioning of the compositions in their intended manner.

While the character of the invention has been given in detail and numerous illustrative examples of the preparationand utility of the compositions of the invention have been described, this has been done largely by way of illustration and with the intention that no limitation should be imposed upon the invention thereby. It will be obvious to those skilled in the art that numerous modifications and" variations of the above illustrative examples may be eflected in the practice of the invention, which is intended to be of the scope oi the appended claims.

We claim:

1. A liquid hydrocarbon oil of the lubricatin class, normally tending to deteriorate at operatsmall amount, sufilcient to retard said deteriora tion, of a polyvalent metal salt of an aliphatic carboxylic acid containing at least one metal carboxylate group attached to an aliphaticcarbon atom, containing at least one other group also attached to an aliphatic carbon atom and selected from the class consisting of COOH, CBSI-L'COOM and CSSM groups, wherein M represents a metal, and containing an oil-solubilizing group.

6. The oil of claim 5', wherein said oil-solubilizing group is a long chain aliphatic group.

7; A liquid hydrocarbon oil of the lubricatinB class, normally tending to deteriorate at operating temperatures encountered in the operation of internal combustion engines, containing a small amount, suillclent to retard said deterioration, of an oil-soluble polyvalent metal salt of an allphatic carboxylic acid containinga metal carboxylate group attached to an aliphatic carbon atom, containing a second group also attached to an aliphatic carbon atom and selected from the class consisting of COOH, CSSI-I, 000M and CSSM groups, wherein M represents a metal, and containing a third group of polar, nature attached to an aliphatic carbon atom not more than about two carbon atoms removed from a metal carboxylate group.

8. A composition oi matter, comprising a major proportion of a hydrocarbon oil of lubricatins viscosity and, dissolved in the 011, about 0.1 to 5 per cent by weight based on finished oil oi a compound represented by the partial formula atom to which CXXY is attached. is an aliphatic carbon atom situated not more than about two carbon atoms removed from said COOM group.

X represents a member of the class consistin oi oxygen and sulfur, and Y represents a member of the class consisting of hydrogen, metals and basic nitrogenous radicals.

9. A composition of matter, comprising a major proportion of a hydrocarbon oil of lubricating -viscosity and about 0.1 to 5 per cent by weight based on finished oil of a compound of the structure YXXC-COOM wherein M represents a polyvalent metal, X repwherein M represents a polyvalent metal, X rep-' resents a member of the class consisting of-oxygen and sulfur, and Y represents a member of the group consisting of hydrogen, metals and basic nitrogenous radicals, said compound containing an oil-solubilizing substituent.

' 11. A composition of matter, comprising a ma jor proportion of a hydrocarbon oil of lubricating Viscosity and about 0.1 to 5 per cent by weight based on finished oil of a compound of the structure yxxo-o-m z-cooivr wherein M represents a polyvalent metal, X represents a member of the class consisting of oxygen and sulfur, and Y represents a member of the group consisting of hydrogen, metals and basic nitrogenous radicals, said compound containing an oil solubilizing substituent.

12. A. petroleum lubricating oil containing about 0.1 to 5 per cent by weight based on finished oil of a compound having the structure wherein M represents a polyvalent metal and R represents an oil-solubilizing group.

13. The composition of claim 12, wherein M is an alkaline earth metal and R is a long chain alkyl roup.

14; The composition of claim 12, wherein M is calcium and R is a long chain alkyl group.

15., A petroleum lubricating oil containing about 0.1-to 5 per cent by'weight based on finished oil of a compound having the structure CH:.COO

wherein M represents a polyvalent metal and R represents an oil-solubilizing group.

16. The composition of claim 15, wherein M is an alkaline eath metal and R is a long chain alkylene group.

18. A petroleum lubricating. oil tending nor-.-

' mally to deteriorate and form carbonaceous de- 0 group, the free dithiocarboxyl group, and neutralized carboxyl and dithiocarboxyl groups.

19. A concentrated dispersion in hydrocarbon lubricating oil of a metal salt of an aliphatic earboxylic acid, said metal salt carrying, on an all- 5 phatic carbon atom not mor than about two carbon atoms removed from a metal carboxylate group, a substituent selected from the class consisting of COOH, CSSH, COOM and CBSM groups, wherein M represents a metal.

BRUCE B. FARRINGTON. JAMES 0. CLAYTON. I DORR H. ETZLER.

I Certificate of Correction Patent No. 2,363,514 November 28, 1944.

BRUCE B. FARRI NGTON ET AL It is hereby certified that errors appear in the printed specification of the above numbered potent requiring correction as follows: Rage 2, first column, line 67, for the formula SnH read SnH page 4, second column, lines 36 to 40 inclusive, strike out the formula and insert instead the followingcoo ommt-ouo-em /Co too lines 71 to 75 inclusive, strike out the formula. en insert instead the following end that the was Letters Patent should be read with these corrections therein that the some mey conform to the record of the case in the Patent Ofiice.

Signed and sealed this 5th day of June, A. D. 1945.

[NEAL] I LEsLm FRAZER,

Acting Gommieezmwe of Pete/ate. 

